I think the problem is that you can't logout of the "members.pl" area, which causes problems for those with multiple products here.
When I go through all the classifieds pages and finally reach the members area, I'm actually in the area for my photopost download. The ONLY way to get into the classifieds area is through the link in the original email sent when I purchased classifieds.
After a bit of futzing around I've noticed the following...
Photopost Members Area: http://www.photopost.com/members/members.pl
Classifieds Members Area: https://www.photopost.com/members/members.pl
Now maybe someone from here CAN INVESTIGATE THEMSELVES and sort it out as I don't think this is the first time this issue has surfaced?